Normality, often represented as "N," is a measure of concentration used in chemistry. It is defined as the number of gram-equivalents of a solute dissolved in one liter of solution. Normality is primarily used in acid-base reactions, where it represents the number of acid or base equivalents present in a given volume of solution.
To prepare a 0.1 N NaOH (sodium hydroxide) solution, you need to follow these steps:
Determine the molar mass of NaOH: The molar mass of NaOH is calculated by adding the atomic masses of its constituent elements: sodium (Na), oxygen (O), and hydrogen (H). Sodium has an atomic mass of 22.99 g/mol, oxygen has an atomic mass of 16.00 g/mol, and hydrogen has an atomic mass of 1.01 g/mol. Thus, the molar mass of NaOH is 22.99 + 16.00 + 1.01 = 40.00 g/mol.
Calculate the number of grams of NaOH required: Since 0.1 N NaOH means 0.1 gram-equivalent of NaOH in one liter of solution, you need to find the weight of NaOH that corresponds to 0.1 mole. To calculate this, use the equation: Weight (in grams) = Normality (N) × Equivalent weight (in grams)
The equivalent weight of NaOH is equal to its molar mass, which is 40.00 g/mol. Therefore: Weight (in grams) = 0.1 N × 40.00 g/mol = 4.00 grams
So, you will need 4.00 grams of NaOH.
Weigh out 4.00 grams of NaOH: Use a balance to accurately weigh 4.00 grams of NaOH.
Dissolve NaOH in distilled water: Take a clean, dry container (such as a beaker) and add approximately 50-70 ml of distilled water. Slowly add the weighed NaOH into the water while stirring continuously until it dissolves completely.
Transfer the solution to a 100 ml volumetric flask: Once the NaOH is completely dissolved, transfer the solution to a 100 ml volumetric flask. Rinse the container used for dissolution to ensure all the NaOH is transferred, and then make up the volume with distilled water to the 100 ml mark on the volumetric flask.
Mix thoroughly: Cap the volumetric flask and mix the solution thoroughly by inverting it several times or using a stirrer.
You have now prepared a 0.1 N NaOH solution in a 100 ml volumetric flask. Remember to handle NaOH with caution as it is a strong base and can cause chemical burns. Take appropriate safety measures, such as wearing gloves and goggles, when working with NaOH.
